ABSTRAKModul fisika berbasis inkuiri terbimbing pada materi listrik dinamis perludikembangkan untuk meningkatkan keterampilan berpikir kritis dan hasil belajar siswa.Penelitian ini bertujuan untuk mengetahui: 1) pengembangan Modul Fisika BerbasisInkuiri Terbimbing, 2) kelayakan produk Modul Fisika Berbasis Inkuiri Terbimbing, 3)efektivitas Modul Fisika Berbasis Inkuiri Terbimbing untuk meningkatkan keterampilanberpikir kritis siswa kelas X SMA/MA.Jenis penelitian ini adalah penelitian pengembangan (Research andDevelopment) termodifikasi dari Borg and Gall (1983). Sampel penelitianpengembangan meliputi: 1) sampel uji coba produk awal sejumlah 2 validator ahli(materi, media dan bahasa), 2 praktisi pendidikan dan 2 teman sejawat, 2) sampel ujicoba lapangan terbatas sejumlah 10 siswa kelas X2 SMA Muhammadiyah 1Temanggung, dan 3) sampel uji lapangan operasional sejumlah 26 siswa kelas X1 SMAMuhammadiyah 1 Temanggung. Instrumen yang digunakan adalah angket, lembarobservasi, wawancara, dan tes. Uji lapangan operasional menggunakan one grouppretest-posttest design. Data keterampilan berpikir kritis (hasil belajar kognitif) siswadiuji menggunakan uji t berpasangan dan dihitung dengan N-gain ternormalisasi.Hasil penelitian pengembangan sebagai berikut: 1) karakteristik pengembanganmodul fisika berbasis inkuiri terbimbing untuk meningkatkan keterampilan berpikirkritis siswa kelas X SMA/MA yaitu menggunakan teknik R&D (research anddevelopment) dari Borg and Gall (1983: 775) termodifikasi melalui 10 tahap dengantahapan terakhir dilakukan diseminasi saja tanpa dilakukannya implementasi produk, 2)kelayakan Modul Fisika Berbasis Inkuiri Terbimbing setelah dilakukannya uji cobaproduk awal, uji coba lapangan terbatas, uji lapangan operasional dan diseminasi danimplementasi didapatkan rata-rata persentase sebesar 85,11% yang dikategorikan?Sangat Baik?, 3) efektivitas Modul Fisika Berbasis Inkuiri Terbimbing untukmeningkatkan keterampilan berpikir kritis siswa didapatkan nilai N-gain dariketerampilan berpikir kritis (hasil belajar kognitif) sebesar 0,564 dikategorikan?Sedang?.Kata kunci: Penelitian Pengembangan, Modul, Inkuiri Terbimbing, dan KeterampilanBerpikir Kritis.ABSTRACTPhysics module based guide inquiry on electro dynamic should be developed toincrease critical thinking skills and students achievement. This research aims are to: 1)identify the develop product of Guided Inquiry-based Physics Module, 2) identify theproperness of Guided Inquiry-based Physics Module, 3) identify the effectiveness ofGuided Inquiry-based Physics Module to Increase Students’ Skill of Critical Thinkingin Class X SMA/MA.This Research and Development (R&D) is modified from Borg and Gall model(1983). Sample of the research were: 1) sample of initial product trial: 2 validations(Contents, design, language), education practitioners and collage friend, 2) sample ofpreliminary field test: 10 students in X2 class SMA Muhammadiyah 1 Temanggung and3) sample of operational field test: 26 students in X1 class SMA Muhammadiyah 1Temanggung. The instruments used were questionnaire, observation sheets, interviewand test. One group pretest-posttest design was used in the operational field test. Data ofcritical thinking skill (students’ cognitive achievement) were tested using paired t testand were scored using N-gain score.Research findings are presented as follow: 1) guided Inquiry-based PhysicsModule to Increase Students’ Skill of Critical Thinking was developed using modifiedmodel of Gall, Borg, and Gall (1983), through: research and data collection, planning,initial product development, initial product trial, product I revision, preliminary fieldtest, product II revision, operational field test, final product revision, dissemination andimplementation; 2) properness of Guided Inquiry-based Physics Module to IncreaseStudents’ Skill of Critical Thinking was identified after initial product trial, preliminary,operational field test and dissemination and implementation, the mean percentage scorewas 85,11% and it was category “Very Good”; 3) effectiveness of Guided Inquiry-basedPhysics Module to Increase Students’ Skill of Critical Thinking was identified from Ngainscore of critical thinking skill (students’ cognitive achievement): 0,564 (“Mediumcategory”).Keywords: Research and Development, Module, Guided Inquiry, Critical ThingkingSkill.