A body flow path in a first housing having an MPU element communicates with an inner flow path and outer flow path formed in an inner heat-dissipating board and an outer heat-dissipating board, respectively, and a pump drives a cooling liquid to circulate in these flow paths. A beam is arranged between a pivot provided in a second housing and a pivot provided in the inner heat-dissipating board, a beam is arranged between the pivot of the inner heat-dissipating board and a pivot provided in the outer heat-dissipating board, and the inner heat-dissipating board and the outer heat-dissipating board are movable to the second housing. According to the operation of opening the second housing, a distance between the second housing and the inner heat-dissipating board, and a distance between the inner flow path and the outer flow path are increased.