A delivery system (1D, 1E) comprising: a catheter, a pusher guide wire (30, 40) inserted into the catheter for delivering a stent (2B, 2C) to a target site, comprising: a core shaft (31, 41); a first coil body (32, 42) covering the core shaft (31, 41) and fixed to the core shaft (31, 41); a second coil body (34, 44) covering the core shaft (31, 41), the second coil body (34, 44) that is fixed to the core shaft (31, 41) at a proximal end side relative to the first coil body (32, 42) and separated from the first coil body (32, 42); and, a tubular member (35, 45) disposed between the first coil body (32, 42) and the second coil body (34, 44) wherein the core shaft (31, 41) is inserted through an inside of the tubular member (35, 45); and the stent (2B, 2C) to be delivered by the pusher guide wire (30, 40), characterized in that the tubular member (35, 45) is not fixed to the core shaft (21, 31, 41), and is capable of moving in a radial direction relative to the core shaft (31, 41) such that the outer periphery of the tubular member (35, 45) makes contact with the inner periphery of the stent (2B, 2C) depending on a curvature of the catheter when the stent (2B, 2C) and the pusher guide wire (30, 40) pass through the inside of a curved blood vessel, wherein the second coil body (34, 44) has a tapered portion (343, 443) with an increasing outer diameter toward a proximal end side, wherein a proximal end portion of the stent (2B, 2C) has a proximal end engagement portion protruding toward the core shaft (31, 41), the proximal end engagement portion of the stent (2B, 2C) is located between the tapered portion (343, 443) and the tubular member (35, 45) in an axial direction of the core shaft (31, 41), and an inner diameter of the stent (2B, 2C) at the proximal end engagement portion is smaller than an outer diameter of the second coil body (34, 44) at the tapered portion (343, 443). a catheter, a pusher guide wire (30, 40) inserted into the catheter for delivering a stent (2B, 2C) to a target site, comprising: a core shaft (31, 41); a first coil body (32, 42) covering the core shaft (31, 41) and fixed to the core shaft (31, 41); a second coil body (34, 44) covering the core shaft (31, 41), the second coil body (34, 44) that is fixed to the core shaft (31, 41) at a proximal end side relative to the first coil body (32, 42) and separated from the first coil body (32, 42); and, a tubular member (35, 45) disposed between the first coil body (32, 42) and the second coil body (34, 44) wherein the core shaft (31, 41) is inserted through an inside of the tubular member (35, 45); and the stent (2B, 2C) to be delivered by the pusher guide wire (30, 40), characterized in that the tubular member (35, 45) is not fixed to the core shaft (21, 31, 41), and is capable of moving in a radial direction relative to the core shaft (31, 41) such that the outer periphery of the tubular member (35, 45) makes contact with the inner periphery of the stent (2B, 2C) depending on a curvature of the catheter when the stent (2B, 2C) and the pusher guide wire (30, 40) pass through the inside of a curved blood vessel, wherein the second coil body (34, 44) has a tapered portion (343, 443) with an increasing outer diameter toward a proximal end side, wherein a proximal end portion of the stent (2B, 2C) has a proximal end engagement portion protruding toward the core shaft (31, 41), the proximal end engagement portion of the stent (2B, 2C) is located between the tapered portion (343, 443) and the tubular member (35, 45) in an axial direction of the core shaft (31, 41), and an inner diameter of the stent (2B, 2C) at the proximal end engagement portion is smaller than an outer diameter of the second coil body (34, 44) at the tapered portion (343, 443). a core shaft (31, 41); a first coil body (32, 42) covering the core shaft (31, 41) and fixed to the core shaft (31, 41); a second coil body (34, 44) covering the core shaft (31, 41), the second coil body (34, 44) that is fixed to the core shaft (31, 41) at a proximal end side relative to the first coil body (32, 42) and separated from the first coil body (32, 42); and, a tubular member (35, 45) disposed between the first coil body (32, 42) and the second coil body (34, 44) wherein the core shaft (31, 41) is inserted through an inside of the tubular member (35, 45); and the stent (2B, 2C) to be delivered by the pusher guide wire (30, 40), characterized in that the tubular member (35, 45) is not fixed to the core shaft (21, 31, 41), and is capable of moving in a radial direction relative to the core shaft (31, 41) such that the outer periphery of the tubular member (35, 45) makes contact with the inner periphery of the stent (2B, 2C) depending on a curvature of the catheter when the stent (2B, 2C) and the pusher guide wire (30, 40) pass through the inside of a curved blood vessel, wherein the second coil body (34, 44) has a tapered portion (343, 443) with an increasing outer diameter toward a proximal end side, wherein a proximal end portion of the stent (2B, 2C) has a proximal end engagement portion protruding toward the core shaft (31, 41), the proximal end engagement portion of the stent (2B, 2C) is located between the tapered portion (343, 443) and the tubular member (35, 45) in an axial direction of the core shaft (31, 41), and an inner diameter of the stent (2B, 2C) at the proximal end engagement portion is smaller than an outer diameter of the second coil body (34, 44) at the tapered portion (343, 443).