Substrate processing method and substrate processing apparatus

An object to be etched, which represents at least one of monocrystalline silicon and polycrystalline silicon, is etched by supplying an alkaline first etching solution to a substrate. An etching step of supplying an alkaline second etching solution to the substrate before or after the first etching solution is supplied to the substrate to etch the object to be etched; the second etching solution contains a compound that prevents hydroxide ions from coming into contact with the object to be etched, the difference between the maximum value and the minimum value of the etching speed of the (110) plane, the (100) plane and the (111) plane of silicon is smaller than that of the first etching solution, and the maximum value of the etching speed is smaller than that of the first etching solution. 通过将碱性的第1蚀刻液供应给基板，而对表示单晶硅与多晶硅中的至少一者的蚀刻对象物施行蚀刻。在将第1蚀刻液供应给基板前或供应后，将碱性的第2蚀刻液供应给基板，而对蚀刻对象物施行蚀刻；该第2蚀刻液含有阻碍氢氧化物离子与蚀刻对象物接触的化合物，且对硅的(110)面、(100)面、及(111)面的蚀刻速度的最大值与最小值差比第1蚀刻液小，蚀刻速度的最大值比第1蚀刻液小。