The present invention provides a manufacturing method of a semiconductor chip, in which the manufacturing yield is excellent, and a kit. According to the present invention, a manufacturing method of a semiconductor chip includes Process 1 of forming an insulating layer on a base material, Process 2 of forming a patterned resist film on the insulating layer, Process 3 of forming the insulating layer having an opening portion by etching the insulating layer with the patterned resist film as a mask, Process 4 of removing the patterned resist film, Process 5 of filling the opening portion of the insulating layer with metal, and Process 6 of performing chemical-mechanical polishing on the insulating layer filled with metal. In at least one process of Process 1 to Process 6, a chemical liquid which includes an organic solvent and metal impurities including at least one metal atom selected from the group consisting of a Fe atom, a Cr atom, a Ni atom, and a Pb atom, and in which the total content of the metal atom is 0.001 to 100 mass ppt is used.