A plate-like heat exchanger is provided with a plate-like structure; one or more flow paths respectively including opened ends, the flow paths being formed in an interior of the plate-like structure and running in a first direction; one or more covering members fixed to the plate-like structure, at least one end of the covering members extending to reach any one or more peripheries of the plate-like structure; one or more crossing flow paths defined by the covering members and the plate-like structure, the crossing flow paths being directed to a second direction intersecting the first direction and respectively being linked with the opened ends of the flow paths; and inflow and outflow ports respectively for inflow and outflow of a fluid, the ports respectively being formed at the ends of the covering members at the peripheries of the plate-like structure and linked with the crossing flow paths.