A method of manufacturing an automotive body including an automotive crashworthiness energy absorbing part that absorbs crashworthiness energy by being axially crushed when a crashworthiness load is input from a front side or a rear side of the automotive body, the method comprising: a part manufacturing process of manufacturing the automotive crashworthiness energy absorbing part; and a body assembly process of assembling the automotive body by attaching the automotive crashworthiness energy absorbing part manufactured in the part manufacturing process to a front portion or a rear portion of the automotive body, wherein the part manufacturing process includes: a pre-coated part manufacturing process of manufacturing a pre-coated part including: a tubular member formed using a hat-shaped section member including a top portion and a side wall portion, and a coating part having quality of material with a strength lower than that of the tubular member, the coating part being disposed with a gap of 0.2 mm to 3 mm on an outer surface of a portion including a corner connecting the top portion and the side wall portion in the tubular member to form a coating film; and a coating film forming process of forming a coating film by: forming a coating layer by electrodeposition coating in an electrodeposition process in at least the gap in the pre-coated part by immersing the pre-coated part in an electrodeposition tank containing an electrodeposition paint, wherein the electrodeposition paint is one of a polyurethane type cationic electrodeposition paint, an epoxy type cationic electrodeposition paint, a urethane cationic electrodeposition paint, an acrylic anionic electrodeposition paint, and a fluororesin electrodeposition paint, and thermally curing the coating layer by a subsequent paint baking process. a part manufacturing process of manufacturing the automotive crashworthiness energy absorbing part; and a body assembly process of assembling the automotive body by attaching the automotive crashworthiness energy absorbing part manufactured in the part manufacturing process to a front portion or a rear portion of the automotive body, wherein the part manufacturing process includes: a pre-coated part manufacturing process of manufacturing a pre-coated part including: a tubular member formed using a hat-shaped section member including a top portion and a side wall portion, and a coating part having quality of material with a strength lower than that of the tubular member, the coating part being disposed with a gap of 0.2 mm to 3 mm on an outer surface of a portion including a corner connecting the top portion and the side wall portion in the tubular member to form a coating film; and a coating film forming process of forming a coating film by: forming a coating layer by electrodeposition coating in an electrodeposition process in at least the gap in the pre-coated part by immersing the pre-coated part in an electrodeposition tank containing an electrodeposition paint, wherein the electrodeposition paint is one of a polyurethane type cationic electrodeposition paint, an epoxy type cationic electrodeposition paint, a urethane cationic electrodeposition paint, an acrylic anionic electrodeposition paint, and a fluororesin electrodeposition paint, and thermally curing the coating layer by a subsequent paint baking process. a pre-coated part manufacturing process of manufacturing a pre-coated part including: a tubular member formed using a hat-shaped section member including a top portion and a side wall portion, and a coating part having quality of material with a strength lower than that of the tubular member, the coating part being disposed with a gap of 0.2 mm to 3 mm on an outer surface of a portion including a corner connecting the top portion and the side wall portion in the tubular member to form a coating film; and a tubular member formed using a hat-shaped section member including a top portion and a side wall portion, and a coating part having quality of material with a strength lower than that of the tubular member, the coating part being disposed with a gap of 0.2 mm to 3 mm on an outer surface of a portion including a corner connecting the top portion and the side wall portion in the tubular member to form a coating film; and a coating film forming process of forming a coating film by: forming a coating layer by electrodeposition coating in an electrodeposition process in at least the gap in the pre-coated part by immersing the pre-coated part in an electrodeposition tank containing an electrodeposition paint, wherein the electrodeposition paint is one of a polyurethane type cationic electrodeposition paint, an epoxy type cationic electrodeposition paint, a urethane cationic electrodeposition paint, an acrylic anionic electrodeposition paint, and a fluororesin electrodeposition paint, and thermally curing the coating layer by a subsequent paint baking process.