There is provided a novel substrate support pin installation jig used when installing a substrate support pin for supporting a circuit substrate. The substrate support pin installation jig (hereinafter, may be simply referred to as a jig) according to the present disclosure includes a main body configured to move relative to a support base, multiple pin accommodating portions provided in the main body, and a positioned portion used for positioning on the support base. The substrate support pin is accommodated and held in at least one of multiple pin accommodating portions in the jig. The jig is placed on the support base in a state where a relative position is specified by the positioned portion. By releasing holding of the substrate support pin, the substrate support pin is installed on the support base, and then the jig is removed.