A general-purpose optical measuring device enables at least measurement of a nucleic acid amplification amount; detection or quantitative measurement by a nucleic acid detection method, an immunoassay method, an enzyme method; or measurement of concentration or absorbance, and a method of the same. There are included a photometric content designation unit, an irradiation reception pair including an emission end that can emit measurement light, and a reception end that can receive light from the emission end, a photometric container that can store measurement target chemical substance solution, and includes a bottom portion having a formed translucent region, a nozzle communicated with a suction discharge mechanism of gas, a flow tube, an optical measurement unit, and a control unit configured to suck and hold the chemical substance solution into the flow tube, or store the chemical substance solution into the photometric container.