PROBLEM TO BE SOLVED: To manufacture a porous composite metal body of high quality, by preventing materials forming a mold from attaching to a porous metal body at the diffusion bonding between a minute metal body and the porous metal body.SOLUTION: A method for manufacturing a porous composite metal body is characterized by: detachably setting up a plurality of positioning pins 14 coming into abutment with an outer circumferential surface of a minute metal body 3 to a lower mold 12; providing a ceramic backing plate 13 having a recess 23 that can fit the end of the side opposite to a contact surface to the minute metal body 3 in a porous metal body 2 on the surface of the lower mold 12 in the portion surrounded by the positioning pins 14; disposing the minute metal body 3 so as to internally touch the positioning pins 14, while fitting the porous metal body 2 in the recess 23 of the ceramic backing plate 13; bringing the porous metal body 2 into a pressing state with the minute metal body 3 by the mold clamping of an upper mold to the lower mold 12; applying heat after extracting the positioning pins 14; and performing diffusion bonding of the porous metal body 3 with the minute metal body.【課題】緻密金属体と多孔質金属体とを拡散接合する際に、型をなす材料が多孔質金属体に付着することを防止し、高品質の多孔質複合金属体を製造する。【解決手段】下型12に、緻密金属体3の外周面に当接する複数の位置決めピン14を着脱可能に立設するとともに、これら位置決めピン14に囲まれた部分における下型12の表面に、多孔質金属体2における緻密金属体3への接触面とは反対側の端部を嵌合可能な凹部23を有するセラミックス当て板13を設けておき、セラミックス当て板13の凹部23内に多孔質金属体2を嵌合した状態で緻密金属体3を位置決めピン14に内接するように配置し、下型12に上型を型締めすることにより多孔質金属体2と緻密金属体3を押圧状態とし、位置決めピン14を抜き取った後に、加熱して多孔質金属体3を緻密金属体に拡散接合する。【選択図】 図6