PURPOSE: To reduce the cost of a fixture, by assembling two or more blocks, where probe pins are stood, and one or more blocks, where no probe pin is stood, into the fixture and making it possible to decompose or reconstitute the fixture.

CONSTITUTION: In respect to a fixture of constituting elements of a testing machine, especially, an in-circuit tester in a logic device, the fixture consists of blocks 201 where probe pins 101 are stood, guide posts 301 for fixing blocks, a fixture frame 401 for fixing guide posts 301, and blocks 211 having no pins; and when fixtures for in-circuit tester for individual circuit substrates to be tested are generated, blocks 201 and 211 are combined properly and are inserted between guide posts 301, and posts 301 are fixed to the fixture frame 401. Thus, the time and the cost for production of the fixture are reduced considerably.