PURPOSE: To eliminate damage of a contact probe, wear of a contact, and to eliminate removal and temporary stock place of a fixture cover at the time of maintenance, inspection by rotating a coverlike body with a bearing as a fulcrum until it is completely closed, i.e., at the former period of cover closing operation, and vertically moving down it to a base at the latter period of the closing operation.

CONSTITUTION: When a coverlike body 6 is closed, the body 6 is received by a force vertically upward to a base 1 by spring energizing means 14. The body 6 is moved vertically upward to a base by the operations of guide means 4, 4a, 5, 5a, 7, 8 and the means 14 at the former period of the closing operation of the body 6, and the body 6 is automatically shifted to its rotating operation after the vertical movement. After shifting, the body can be closed by other means such as an input, etc. Then, the body 6 is rotated at the former period of closing, and moved vertically to the base 1 without axial rotation by the guide means 4, 4a, 5, 5a, 7, 8 at the latter period of closing. Thus, damage of a contact probe, wear of a contact are prevented, and removal and temporary stock place of a fixture cover at the time of maintenance, inspection can be eliminated.