An exhaust control device for an internal combustion engine purifies exhaust gas lead to a turbine and enhances supercharging performance. The exhaust control device is applied to an internal combustion engine (1) having cylinders (2) and a turbo supercharger (7). In the exhaust control device, an exhaust path (4) has a first branch path (21) for connection between the exhaust side of #1 and #4 cylinders (2) and the turbine (7b) and having provided in it a start catalyst (23), and the exhaust path (4)also has a second branch path (22) for connection between the exhaust side of #2 and #3 cylinders (2) and the turbine (7b) and communicated with that portion of the first branch path (21) which is on the upstream of the start catalyst (23). An exhaust switchover valve (26) capable of being switched between an introduction position (P1) and a prevention position (P2) is provided at a communication section (25) with which the first branch path (21) and the second branch path (22) are communicated. At the introduction position (P1), exhaust from the #2 and #3 cylinders (2) is introduced to the start catalyst (23), and at the prevention position (P2), the introduction is prevented. An ECU (30) switches the position of the exhaust switchover valve (26) based on operating conditions of the internal combustion engine (1).