An automatic control device for controlling a control target, comprising: a control section that is configured to calculate an operation amount of the control target based on a difference between a current value and a target value of the control amount of the control target; a first filter that is configured to output a first output value after using a specified filter coefficient to perform filtering of the operation amount calculated by the control section, a second filter, arranged in parallel with the first filter, that is configured to output a second output value after using a specified filter coefficient different to the filter coefficient of the first filter to perform filtering of the operation amount calculated by the control section; the automatic control device being characterized by a switching section that is configured to switch to and from the first output value of the first filter and the second output value of the second filter and to send one of the output values (103, 104) to the control target, wherein a first filter coefficient or a second filter coefficient may be selectively input to the first filter, a third filter coefficient may be input to the second filter, such that a time constant of the first output value of the first filter when the first filter coefficient or the second filter coefficient is input to the first filter is larger than a time constant of the second output value of the second filter when the third filter coefficient is input to the second filter, and in a case in which the filter coefficient input to the first filter is switched from the first filter coefficient to the second filter coefficient, or switched from second filter coefficient to the first filter coefficient, in a state with the first output value of the first filter being sent to the control target, the switching section is configured to switch to a state in which the second output value of the second filter is being sent to the control target before switching the filter coefficient of the first filter and to switch to a state in which the first output value of the first filter is being sent to the control target after the filter coefficient to be input has been switched to the first filter. a control section that is configured to calculate an operation amount of the control target based on a difference between a current value and a target value of the control amount of the control target; a first filter that is configured to output a first output value after using a specified filter coefficient to perform filtering of the operation amount calculated by the control section, a second filter, arranged in parallel with the first filter, that is configured to output a second output value after using a specified filter coefficient different to the filter coefficient of the first filter to perform filtering of the operation amount calculated by the control section; the automatic control device being characterized by a switching section that is configured to switch to and from the first output value of the first filter and the second output value of the second filter and to send one of the output values (103, 104) to the control target, wherein a first filter coefficient or a second filter coefficient may be selectively input to the first filter, a third filter coefficient may be input to the second filter, such that a time constant of the first output value of the first filter when the first filter coefficient or the second filter coefficient is input to the first filter is larger than a time constant of the second output value of the second filter when the third filter coefficient is input to the second filter, and in a case in which the filter coefficient input to the first filter is switched from the first filter coefficient to the second filter coefficient, or switched from second filter coefficient to the first filter coefficient, in a state with the first output value of the first filter being sent to the control target, the switching section is configured to switch to a state in which the second output value of the second filter is being sent to the control target before switching the filter coefficient of the first filter and to switch to a state in which the first output value of the first filter is being sent to the control target after the filter coefficient to be input has been switched to the first filter.