In this electric component assembly, an electric component can be assembled without the use of jigs, and, by eliminating the space for a jig arrangement, it is possible to achieve greater compactnessand a simplified configuration of the electric component. This electric component assembly is provided with a housing (202) to which the electric component is attached, and the electric component andthe housing (202) are fixed to one surface of a substrate (100). The electric component is provided with a connection terminal pressed into a through-hole (201a) of a control substrate (201) of the housing (202), and the insertion direction of the connection terminal into the through-hole (201a) is the direction of attachment to the housing (202). A rib (25) is provided projecting from one of theelectric component and the housing (202), and a recessed groove (226) for press-fitting the rib (25) is provided in the other. Press-fitting the rib (25) into the groove (226) restricts the electric component from moving in a direction intersecting the attachment direction and from rotating around an axis parallel to the attachment direction.