An electronic unit attaching structure includes an electronic unit (30) having a plurality of connector connection portions (33, 34) and an electronic unit attachment (20) having a plurality of connectors (C1, C2) correspond to the plurality of the connector connection portions. The electronic unit attaching structure is configured to allow first connection and second connection in this order when the electronic unit (30) is attached to the electronic unit attachment (20). The first connection is a connection of first part (C2) of the plurality of the connectors with first part (34) of the plurality of the connector connection portions. The second connection is a connection of second part (C1) of the plurality of the connectors with second part (33) of the plurality of the connector connection portions.