An engine device comprising: an engine which serves as a power source; an exhaust gas purifying filter device which is arranged in an exhaust gas path of the engine; and control means which executes a low rotation control for lowering an engine speed to a predetermined low idle rotating speed at a time when a previously set low rotation condition is established, wherein the engine device is mounted on a working machine which comprises a traveling portion and a working portion that are powered by the engine, the working machine is provided with selection operating means selectively operating the low rotation control, the control means is structured such as to maintain the engine speed at a high idle rotating speed which is higher than the low idle rotating speed, for suppressing a reduction of an exhaust gas temperature at a time when a previously set forced regeneration condition is established after the low rotation condition is established, whereas to maintain the engine speed at the low idle rotating speed at a time when the forced regeneration condition is not established, and to lower the engine speed to the low idle rotating speed at a time when only the forced regeneration condition dissolves after setting the engine speed to the high idle rotating speed, whereas to execute the forced regeneration control of the filter device at a time when only the low rotation condition dissolves, wherein the low rotation condition is established at a time when the working portion is not operated and the traveling portion stops under a state of operating the selection operating means so as to allow the low rotation control. an engine which serves as a power source; an exhaust gas purifying filter device which is arranged in an exhaust gas path of the engine; and control means which executes a low rotation control for lowering an engine speed to a predetermined low idle rotating speed at a time when a previously set low rotation condition is established, wherein the engine device is mounted on a working machine which comprises a traveling portion and a working portion that are powered by the engine, the working machine is provided with selection operating means selectively operating the low rotation control, the control means is structured such as to maintain the engine speed at a high idle rotating speed which is higher than the low idle rotating speed, for suppressing a reduction of an exhaust gas temperature at a time when a previously set forced regeneration condition is established after the low rotation condition is established, whereas to maintain the engine speed at the low idle rotating speed at a time when the forced regeneration condition is not established, and to lower the engine speed to the low idle rotating speed at a time when only the forced regeneration condition dissolves after setting the engine speed to the high idle rotating speed, whereas to execute the forced regeneration control of the filter device at a time when only the low rotation condition dissolves, wherein the low rotation condition is established at a time when the working portion is not operated and the traveling portion stops under a state of operating the selection operating means so as to allow the low rotation control.