To avoid damage of compositional members, e.g. tube members, without controlling the solid ratio at the time of cold storage by providing a plurality of tube members and a cold storage member containing cold storage material in a bag member and arranging the cold storage member so that the bag member touches a part of the periphery of the plurality of tube members simultaneously.

A heat exchanger 10 comprises a plurality of tube members 1 and a cold storage member 2 containing cold storage material in a bag member 3. The cold storage member 2 is arranged such that the bag member 3 touches a part of the periphery of the plurality of tube members 1 simultaneously and the bag member 3 is made of a flexible material. Refrigerant is fed through cooling ducts 5a, 5b and the cold storage member 2 stores cold through the wall of the tube member and the bag member 3. The cold storage member 2 is expanded but since the cold storage material is contained in the bag member 3, the tube members 1 are substantially bent in the direction not restricted by the tube members 1. Consequently, damage of compositional members, e.g. tube members, due to cold storage can be avoided.