This paper describes the numerical heat transfer and flow characteristics of a slit-type impinging jet in a flow passage partially filled with a porous medium. The porous medium is a dispersed matter. Numerical calculation was performed in the three kinds of the constructions and in various thicknesses of the porous medium. The working fluid was herium and the temperature dependency of its thermalconductivity and kinematic viscosity was consiered. Velocity, temperature and density distributions in a flow passage were obtained. Additionally, Nusselt numbers on the impingement surface were evaluated