A heat-treated steel sheet member having a chemical composition comprising, by mass%: C: 0.05 to 0.50%; Si: 0.50 to 5.0%; Mn: 1.5 to 4.0%; P: 0.05% or less; S: 0.05% or less; N: 0.01% or less; Ti: 0.01 to 0.10%; B: 0.0005 to 0.010%; Cr: 0 to 1.0%; Ni: 0 to 2.0%; Cu: 0 to 1.0%; Mo: 0 to 1.0%; V: 0 to 1.0%; Ca: 0 to 0.01%; Al: 0 to 1.0%; Nb: 0 to 1.0%; REM: 0 to 0.1%; and the balance: Fe and impurities, wherein the steel sheet member has a steel micro-structure comprising: martensite of which a volume ratio is 95% or higher as measured by etching with Nital and observation under an optical microscope; and retained austenite of which a volume ratio is 0.2 to 1.0%, as measured by x-ray diffraction, a number density of retained carbides being present in the steel sheet member and each having circle-equivalent diameters of 0.1 μm or larger is 4.0 × 10 3 /mm 2 or lower, the number density of retained carbide being determined by: etching the surface of steel sheet for heat treatment using a picral solution, magnifying 2000 times under a scanning electron microscope, observing in a number of plurality of visual fields and counting the number of visual fields where carbides having circle-equivalent diameters of 0.1 μm or larger with an aspect ratio of 3 or lower were present, and a number per 1 mm 2 being calculated, a tensile strength is 1.4 GPa or higher, and a yield ratio is 0.65 or higher, the tensile strength and the yield ratio being determined in conformance with the specifications of ASTM standard E8. C: 0.05 to 0.50%; Si: 0.50 to 5.0%; Mn: 1.5 to 4.0%; P: 0.05% or less; S: 0.05% or less; N: 0.01% or less; Ti: 0.01 to 0.10%; B: 0.0005 to 0.010%; Cr: 0 to 1.0%; Ni: 0 to 2.0%; Cu: 0 to 1.0%; Mo: 0 to 1.0%; V: 0 to 1.0%; Ca: 0 to 0.01%; Al: 0 to 1.0%; Nb: 0 to 1.0%; REM: 0 to 0.1%; and the balance: Fe and impurities, wherein the steel sheet member has a steel micro-structure comprising: martensite of which a volume ratio is 95% or higher as measured by etching with Nital and observation under an optical microscope; and retained austenite of which a volume ratio is 0.2 to 1.0%, as measured by x-ray diffraction, a number density of retained carbides being present in the steel sheet member and each having circle-equivalent diameters of 0.1 μm or larger is 4.0 × 10 3 /mm 2 or lower, the number density of retained carbide being determined by: etching the surface of steel sheet for heat treatment using a picral solution, magnifying 2000 times under a scanning electron microscope, observing in a number of plurality of visual fields and counting the number of visual fields where carbides having circle-equivalent diameters of 0.1 μm or larger with an aspect ratio of 3 or lower were present, and a number per 1 mm 2 being calculated, a tensile strength is 1.4 GPa or higher, and a yield ratio is 0.65 or higher, the tensile strength and the yield ratio being determined in conformance with the specifications of ASTM standard E8. martensite of which a volume ratio is 95% or higher as measured by etching with Nital and observation under an optical microscope; and retained austenite of which a volume ratio is 0.2 to 1.0%, as measured by x-ray diffraction, a number density of retained carbides being present in the steel sheet member and each having circle-equivalent diameters of 0.1 μm or larger is 4.0 × 10 3 /mm 2 or lower, the number density of retained carbide being determined by: etching the surface of steel sheet for heat treatment using a picral solution, magnifying 2000 times under a scanning electron microscope, observing in a number of plurality of visual fields and counting the number of visual fields where carbides having circle-equivalent diameters of 0.1 μm or larger with an aspect ratio of 3 or lower were present, and a number per 1 mm 2 being calculated, a tensile strength is 1.4 GPa or higher, and a yield ratio is 0.65 or higher, the tensile strength and the yield ratio being determined in conformance with the specifications of ASTM standard E8.