A power conversion device comprising: a carrier generating unit that generates a carrier of a particular set carrier frequency during a certain continuation time; a setting unit that sets the continuation time to be random and sets one carrier frequency among a plurality of mutually-different carrier frequencies as the set carrier frequency; a PWM signal generating unit that generates a PWM signal based on the carrier generated by the carrier generating unit; and a power conversion unit that executes a power conversion based on the PWM signal and supplies converted power to a load; characterized in that the setting unit includes: a random number generating unit that generates a random number; and a transition determining unit that determines whether or not the currently set carrier frequency is caused to transit to a different carrier frequency based on the generated random number and a particular set transition probability value, and wherein, in a case where a result of the determination made by the transition determining unit is a transition, the setting unit sets the set carrier frequency to a different carrier frequency and sets one transition probability value among a plurality of mutually-different transition probability values as the set transition probability value; wherein the power conversion device further comprises a value determining unit, to which a mechanical resonance characteristic of the load is input, and which determines at least one side of the plurality of carrier frequencies and the plurality of transition probability values based on the input mechanical resonance characteristic. a carrier generating unit that generates a carrier of a particular set carrier frequency during a certain continuation time; a setting unit that sets the continuation time to be random and sets one carrier frequency among a plurality of mutually-different carrier frequencies as the set carrier frequency; a PWM signal generating unit that generates a PWM signal based on the carrier generated by the carrier generating unit; and a power conversion unit that executes a power conversion based on the PWM signal and supplies converted power to a load; characterized in that the setting unit includes: a random number generating unit that generates a random number; and a transition determining unit that determines whether or not the currently set carrier frequency is caused to transit to a different carrier frequency based on the generated random number and a particular set transition probability value, and wherein, in a case where a result of the determination made by the transition determining unit is a transition, the setting unit sets the set carrier frequency to a different carrier frequency and sets one transition probability value among a plurality of mutually-different transition probability values as the set transition probability value; wherein the power conversion device further comprises a value determining unit, to which a mechanical resonance characteristic of the load is input, and which determines at least one side of the plurality of carrier frequencies and the plurality of transition probability values based on the input mechanical resonance characteristic. a random number generating unit that generates a random number; and a transition determining unit that determines whether or not the currently set carrier frequency is caused to transit to a different carrier frequency based on the generated random number and a particular set transition probability value, and wherein, in a case where a result of the determination made by the transition determining unit is a transition, the setting unit sets the set carrier frequency to a different carrier frequency and sets one transition probability value among a plurality of mutually-different transition probability values as the set transition probability value; wherein the power conversion device further comprises a value determining unit, to which a mechanical resonance characteristic of the load is input, and which determines at least one side of the plurality of carrier frequencies and the plurality of transition probability values based on the input mechanical resonance characteristic.