Provided is an electronic controller which enables an opening direction of a connector to be set along an electronic circuit board. The electronic controller includes first guiding projections (7a) and second guiding projections (7b) formed on a cover (2), and first guiding grooves (8a) to be brought into engagement with the first guiding projections (7a) and second guiding grooves (8b) to be brought into engagement with the second guiding projections (7b), which are formed on pin headers (4). The first guiding projections (7a) and the second guiding projections (7b) move respectively along the first guiding grooves (8a) and the second guiding grooves (8b). As a result, the pin headers (4) turn to be assembled to housings (14).