PURPOSE: To simplify assembling work and perform positive wiring connection.

CONSTITUTION: A molded roof is formed of a first and a second molded plates 110, 210. A work opening 116 is formed in the first molded plate 110; and electrical equipment such as a room lamp 141 and a map lamp 144, and also roof harness 120 for wiring-connecting these are fitted to the first molded plate 110 to form a main module 100. Non-electrical equipment such as a rear view mirror 230 and a sun visor 240 is fitted to the second molded plate 210 to form a sub-module 200. After fitting the main module 100 to the main region under a body ceiling 51, the sub-module 200 is fitted from the remaining region under the body ceiling 51 to the work opening 116 in such a way as to cover the lower part thereof. Assembling can be thereby performed with this simple work of fitting both modules 100, 200. The wiring connection and the like of electrical equipment can be performed by a worker positively through visual observation.