The present invention provides a solid-phase catalyst for decomposing hydrogen peroxide comprising a permanganate salt and a manganese (II) salt. The solid-phase catalyst stays a solid state in the form of nanoparticles at the time of hydrogen peroxide decomposition, and thus can be recovered for reuse and also has an excellent decomposition rate. In the method for producing a solid-phase catalyst for decomposing hydrogen peroxide according to the present invention, a solid-phase catalyst is produced from a solution containing a permanganate salt, a manganese (II) salt, and an organic acid, so that the produced solid-phase catalyst is precipitated as a solid component even after a catalytic reaction, and thus is reusable and environmentally friendly, and cost reduction can be achieved through the simplification of a catalyst production technique.