Abstract: An electroless platinum plating solution is disclosed that can be subjected to plating processing with high deposition efficiency, does not self-decompose even when it does not contain sulfur or heavy metals, and has excellent bath stability, and an electroless platinum plating solution that can suppresses out-of-pattern deposition of platinum and perform platinum plating only on a necessary portion. An electroless platinum plating solution is disclosed that contains a soluble platinum salt, a complexing agent and any of a borohydride compound, an aminoborane compound and a hydrazine compound, and has a pH of 7 or more, adding a specific hydroxymethyl compound represented by the following formula (1) or a salt thereof: R1—CH2—OH??(1) wherein R1 is an atomic group having an aldehyde group or a ketone group.

Abstract: An electroless platinum plating solution is disclosed that can be subjected to plating processing with high deposition efficiency, does not self-decompose even when it does not contain sulfur or heavy metals, and has excellent bath stability, and an electroless platinum plating solution that can suppresses out-of-pattern deposition of platinum and perform platinum plating only on a necessary portion. An electroless platinum plating solution is disclosed that contains a soluble platinum salt, a complexing agent and any of a borohydride compound, an aminoborane compound and a hydrazine compound, and has a pH of 7 or more, adding a specific hydroxymethyl compound represented by the following formula (1) or a salt thereof: R1—CH2—OH??(1) wherein R1 is an atomic group having an aldehyde group or a ketone group.