Motivation plays an essential part in learning English which stimulates students to learn. If there are obstructions, the student’s motivation can be down. In this case, instrumental motivation commonly happens in the EFL student context because of the use of English in several fields. Instrumental motivation is someone's desire to learn something for benefit. However, the existence of instrumental motivation is rarely noticed. In addition, students’ motivation can be obstructed by these several things. Facing this problem, this study explored how the students’ instrumental motivation is and, the factors that obstruct their motivation, and how the students to overcome the obstructing factors. It was qualitative research, specifically case study, to explore the issue of students’ instrumental motivation in learning English which was infrequently identified as the kind of motivation that commonly appears on EFL students. The participants were the students of a secondary public school in Kudus. The students’ instrumental motivation was categorized as high level since they mostly learned English for instrumental orientations. Even so, their motivation fluctuated in learning, which was affected by four obstructing factors, including difficulty in learning, teaching method, classmates, and task-related. It can be concluded that the students’ instrumental motivation to learn English was at a high level, even though several times the students had fluctuation toward their motivation that was affected by four obstructing factors which led to demotivation. In short, it can be implied that instrumental motivation takes a role in English learning process for the students. However, there are obstructing factors that affects the students’ motivation. Thus, it is important to the students and teacher overcome these factors so that the English learning process can be held well To overcome the factors, the students do several activities related to English that they like such as watching videos or movies and listening to English songs which can be an insight for the students and teacher to overcome the obstructing factors.