A laser module (1, 201, 301) comprising: at least one laser device (20, 30) configured to emit a laser beam (L1, L2) including a major polarization component and a minor polarization component having a power lower than a power of the major polarization component and a polarization direction inclined at an angle of 90 degrees with respect to the major polarization component; and an optical fiber configured to externally output the major polarization component of the laser beam (L1, L2), wherein the laser module (1, 201, 301) further comprises: a package housing (10, 210, 310) that houses the at least one laser device (20, 30) and includes a minor polarization component irradiation portion provided at a position that is different from a portion where the optical fiber is provided; a beam splitter configured to split the laser beam (L1, L2) into the major polarization component and the minor polarization component so that the major polarization component is directed and optically coupled to the optical fiber and that the minor polarization component is directed to the minor polarization component irradiation portion of the package housing (10, 210, 310); and at least one temperature measurement element attached to the package housing (10, 210, 310) and configured to detect a temperature change of the minor polarization component irradiation portion (17, 217, 317). at least one laser device (20, 30) configured to emit a laser beam (L1, L2) including a major polarization component and a minor polarization component having a power lower than a power of the major polarization component and a polarization direction inclined at an angle of 90 degrees with respect to the major polarization component; and an optical fiber configured to externally output the major polarization component of the laser beam (L1, L2), wherein the laser module (1, 201, 301) further comprises: a package housing (10, 210, 310) that houses the at least one laser device (20, 30) and includes a minor polarization component irradiation portion provided at a position that is different from a portion where the optical fiber is provided; a beam splitter configured to split the laser beam (L1, L2) into the major polarization component and the minor polarization component so that the major polarization component is directed and optically coupled to the optical fiber and that the minor polarization component is directed to the minor polarization component irradiation portion of the package housing (10, 210, 310); and at least one temperature measurement element attached to the package housing (10, 210, 310) and configured to detect a temperature change of the minor polarization component irradiation portion (17, 217, 317). a package housing (10, 210, 310) that houses the at least one laser device (20, 30) and includes a minor polarization component irradiation portion provided at a position that is different from a portion where the optical fiber is provided; a beam splitter configured to split the laser beam (L1, L2) into the major polarization component and the minor polarization component so that the major polarization component is directed and optically coupled to the optical fiber and that the minor polarization component is directed to the minor polarization component irradiation portion of the package housing (10, 210, 310); and at least one temperature measurement element attached to the package housing (10, 210, 310) and configured to detect a temperature change of the minor polarization component irradiation portion (17, 217, 317).