A battery temperature control unit 1 for controlling a temperature of an internal space 21 of a module case 22 is provided. The battery temperature control unit 1 includes a unit case 3 which is arranged in the internal space 21 of the module case 22 and includes an air flow passage 4 inside the unit case 3. The battery temperature control unit 1 further includes a heat exchanger 11 arranged in the air flow passage 4. The unit case 3 includes a module opening sealing portion 31, which seals a module opening 24 formed in a wall surface of the module case 22. A module sealing surface 32 is formed in the module opening sealing portion 31, which closes the module opening 24 from an internal space 21 side. A first communication hole 36 and a second communication hole 37 are also formed in the module opening sealing portion 31, which allow the outside of the module case 22 and the inside of the unit case 3 to communicate with each other.