Critical thinking is related to several other abilities, such as decision making and problem solving ability. This study aims to identify measuring power of the critical thinking skills test and calculating parameter test for Physics Education students. The subjects are 44 students with age ranges from 18 to 21 years old. The results of this study indicate the level of critical thinking skills of physics education program students in the low category. This test has moderate reliability coefficient of 0.64, with the most difficult item number is the number 5 and the easiest one is 21 from Rasch Model. Items in the instrument has moderate level of difficulty for physics education students. Moreover, item discrimination of the instrument is quite good, with 9 items which could measure critical thinking skills of physics education students of Universitas Pendidikan Indonesia without creating confusion or misconception.