An electric junction box for a vehicle is assembled by fitting and locking a connector through an aperture provided in a main case; the aperture being used for fitting the connector that holds a retainer at a temporary latch location, the retainer providing a double latch for a terminal; inserting and latching the terminal of an electric wire into the connector; and pushing the retainer into a full latch position. A recess for retainer operation is provided at a location facing the retainer and on a surrounding wall of the main case that surrounds the aperture.