A main body chassis 101 in which a navigation side connector 109 is positioned and fixed, and a display part chassis 203 in which an LCD side connector 205 is positioned and fixed are positioned by abutting a pair of positioning bosses 116 of each of positioning parts 115a and 115b against both-shoulder portions 214 of each of positioning protruding pieces 211a and 211b, and are secured with screws; whether the navigation side connector 109 and the LCD side connector 205 are connected or not can be confirmed by presence or absence of a fitting between a fitting pawl 118 of the outer wall surface and a fitting hole 213.