There is provided a rotary type regenerative heat exchanger which can effectively prevent an air bypass leak or a gas bypass leak. A rotary type regenerative heat exchanger of the present invention has a rotor (4) rotating around a central shaft (2), a heat accumulator (8) which is constructed in a manner that an air (A) of being a heated fluid and a gas (G) of being a heating fluid filled in the rotor alternately pass therethrough by a rotation of the rotor to repeat heat accumulation and radiation, and a housing provided so as to house the rotor. Further, the rotary type regenerative heat exchanger comprises: a branch pipe (41, 47, 55) for taking out a part of the heating fluid; a seal gas fan (42, 48, 56) for pressurizing the taken-out heating fluid to a predetermined pressure; and a seal gas introducing duct (46, 52) which is provided in the housing so as to introduce the pressurized heating fluid into a predetermined space formed between the rotor and the housing.