A temperature adjustment device includes a cooling member and a connecting member. The cooling member consists of a first plate and a second plate. The first plate is thermally abutted against a heat-generating member. The second plate is stacked on a lower surface of the first plate to define a cooling space with the first plate, the cooling space a cooling medium flows through, and being configured to include an inlet and an outlet of the cooling medium on a bottom surface facing against the first plate. The connecting member is the connecting member to a temperature adjustment circuit, and that is configured with a tube member having a flat part. The connecting member includes a connecting port connected to the inlet or the outlet on the flat part, and that is laminated and arranged on the second plate such that the flat part is abutted against the second plate.