The authors have developed a performance test, CPTOP2 (Cognitive Performance Test of Productivity), which consists of four task tests to evaluate cognitive abilities of office workers in order to quantitatively and objectively evaluate their productivity by controlling office environment. In addition, the testing time of CPTOP2 becomes shorter than conventional CPTOP2 in order to introduce it in evaluation of actual office environment. In this study, two subject experiments were conducted to verify its function and accuracy. The function of CPTOP2 was verified by measuring brain activity by fNIRS when conducting CPTOP2 test. The accuracy of CPTOP2 was verified by comparing improvement of performance indexes of CPTOP2 with that of simulated office work.