A method of manufacturing an electronic component-embedded board is provided which is capable of suppressing warpage without requiring complicated processes at low cost and which offers high productivity and economic efficiency. The light source illuminates a sampling plane of a mouse. The venturi insert also includes a second central bore extending therethrough. The method then selects a candidate sub string for each sub string length based on estimated selectivities of the substrings. A rod hole is drilled using the guide hole as a guide.