A wearable suit configured to assist muscular strength of a user, the wearable suit comprising: a body unit; a fixing unit configured to fix the body unit to an upper body of the user; an arm coupling unit coupled to at least a portion of an arm of the user; an arm connecting unit configured to connect the body unit and the arm coupling unit to each other; and a power supply unit configured to supply electric power to the body unit, wherein the body unit comprises: a housing defining an accommodating space therein; and a muscular strength assistance unit disposed inside the housing, wherein the muscular strength assistance unit comprises: at least one muscular strength assistance spring comprised of a shape memory alloy material; a plurality of terminals electrically connected to the power supply unit and the muscular strength assistance spring; and a plurality of supporting members supporting the at least one muscular strength assistance spring and the plurality of terminals, wherein each of the plurality of terminals is formed on each of the plurality of supporting members, wherein at least one of the plurality of supporting members is connected to the arm connecting unit and moves when the at least one muscular strength assistance spring is contracted or expanded to assist the muscular strength of the user, wherein at least another etherof the plurality of supporting members is fixed to the housing, wherein the at least one muscular strength assistance spring is expanded when the user extends the arm, and wherein the at least one muscular strength assistance spring is contracted by heat generated by the electric power and electrical resistance of the at least one muscular strength assistance spring. a body unit; a fixing unit configured to fix the body unit to an upper body of the user; an arm coupling unit coupled to at least a portion of an arm of the user; an arm connecting unit configured to connect the body unit and the arm coupling unit to each other; and a power supply unit configured to supply electric power to the body unit, wherein the body unit comprises: a housing defining an accommodating space therein; and a muscular strength assistance unit disposed inside the housing, wherein the muscular strength assistance unit comprises: at least one muscular strength assistance spring comprised of a shape memory alloy material; a plurality of terminals electrically connected to the power supply unit and the muscular strength assistance spring; and a plurality of supporting members supporting the at least one muscular strength assistance spring and the plurality of terminals, wherein each of the plurality of terminals is formed on each of the plurality of supporting members, wherein at least one of the plurality of supporting members is connected to the arm connecting unit and moves when the at least one muscular strength assistance spring is contracted or expanded to assist the muscular strength of the user, wherein at least another etherof the plurality of supporting members is fixed to the housing, wherein the at least one muscular strength assistance spring is expanded when the user extends the arm, and wherein the at least one muscular strength assistance spring is contracted by heat generated by the electric power and electrical resistance of the at least one muscular strength assistance spring. a housing defining an accommodating space therein; and a muscular strength assistance unit disposed inside the housing, wherein the muscular strength assistance unit comprises: at least one muscular strength assistance spring comprised of a shape memory alloy material; a plurality of terminals electrically connected to the power supply unit and the muscular strength assistance spring; and a plurality of supporting members supporting the at least one muscular strength assistance spring and the plurality of terminals, wherein each of the plurality of terminals is formed on each of the plurality of supporting members, wherein at least one of the plurality of supporting members is connected to the arm connecting unit and moves when the at least one muscular strength assistance spring is contracted or expanded to assist the muscular strength of the user, wherein at least another etherof the plurality of supporting members is fixed to the housing, wherein the at least one muscular strength assistance spring is expanded when the user extends the arm, and wherein the at least one muscular strength assistance spring is contracted by heat generated by the electric power and electrical resistance of the at least one muscular strength assistance spring. at least one muscular strength assistance spring comprised of a shape memory alloy material; a plurality of terminals electrically connected to the power supply unit and the muscular strength assistance spring; and a plurality of supporting members supporting the at least one muscular strength assistance spring and the plurality of terminals, wherein each of the plurality of terminals is formed on each of the plurality of supporting members, wherein at least one of the plurality of supporting members is connected to the arm connecting unit and moves when the at least one muscular strength assistance spring is contracted or expanded to assist the muscular strength of the user, wherein at least another etherof the plurality of supporting members is fixed to the housing, wherein the at least one muscular strength assistance spring is expanded when the user extends the arm, and wherein the at least one muscular strength assistance spring is contracted by heat generated by the electric power and electrical resistance of the at least one muscular strength assistance spring.