A catalyst-turbocharger combination comprising: a catalyst device configured to be disposed in an exhaust passage of an internal combustion engine; and a forced-induction device including a turbine housing that houses a turbine wheel, the catalyst device comprising: a catalyst configured to purify exhaust gas; a heating element configured to heat the catalyst by generating heat when energized; and a case that is a pipe accommodating the catalyst and the heating element, wherein a direction in which exhaust gas flows through the exhaust passage is defined as a gas discharging direction, the case includes an end portion on an upstream side in the gas discharging direction, the heating element includes an end on an upstream side in the gas discharging direction, the end portion of the case protrudes toward an upstream side of the end of the heating element in the gas discharging direction, and is an insulating portion that insulates electricity, a surface of the end portion of the case is covered with an insulating material, such that the end portion of the case is an insulating portion, the catalyst device further comprises an outer tube that is separated from the end portion of the case in a radial direction to cover the end portion, the outer tube is formed by the turbine housing, and the turbine housing includes a cylindrical gas discharge portion that is coaxial with the catalyst device. a catalyst device configured to be disposed in an exhaust passage of an internal combustion engine; and a forced-induction device including a turbine housing that houses a turbine wheel, the catalyst device comprising: a catalyst configured to purify exhaust gas; a heating element configured to heat the catalyst by generating heat when energized; and a case that is a pipe accommodating the catalyst and the heating element, wherein a direction in which exhaust gas flows through the exhaust passage is defined as a gas discharging direction, the case includes an end portion on an upstream side in the gas discharging direction, the heating element includes an end on an upstream side in the gas discharging direction, the end portion of the case protrudes toward an upstream side of the end of the heating element in the gas discharging direction, and is an insulating portion that insulates electricity, a surface of the end portion of the case is covered with an insulating material, such that the end portion of the case is an insulating portion, the catalyst device further comprises an outer tube that is separated from the end portion of the case in a radial direction to cover the end portion, the outer tube is formed by the turbine housing, and the turbine housing includes a cylindrical gas discharge portion that is coaxial with the catalyst device. a catalyst configured to purify exhaust gas; a heating element configured to heat the catalyst by generating heat when energized; and a case that is a pipe accommodating the catalyst and the heating element, wherein a direction in which exhaust gas flows through the exhaust passage is defined as a gas discharging direction, the case includes an end portion on an upstream side in the gas discharging direction, the heating element includes an end on an upstream side in the gas discharging direction, the end portion of the case protrudes toward an upstream side of the end of the heating element in the gas discharging direction, and is an insulating portion that insulates electricity, a surface of the end portion of the case is covered with an insulating material, such that the end portion of the case is an insulating portion, the catalyst device further comprises an outer tube that is separated from the end portion of the case in a radial direction to cover the end portion, the outer tube is formed by the turbine housing, and the turbine housing includes a cylindrical gas discharge portion that is coaxial with the catalyst device.