A work machine, comprising: a telescopic boom including a first boom element (414, 142) and a second boom element (142, 143) that are telescopically overlapped with each other; an actuator that extends and retracts the telescopic boom; a power source; an electric drive source that is provided in the actuator and drives using power supplied from the power source, a number of the electric drive source is one; an operating unit (45, 46) that operates based on power of the electric drive source; an electric circuit capable of switching between a drive state in which a supply of power from the power source to the electric drive source is allowed to drive the electric drive source, and a braking state in which the supply of power from the power source to the electric drive source stops to generate a braking force to be applied to the electric drive source; and a control unit that controls the switching between the drive state and the braking state, characterized in that the operating unit (45, 46) includes: a first connecting mechanism that operates based on the power of the electric drive source and switches between a connected state and a disconnected state of the first boom element (141, 142) and the actuator; and a second connecting mechanism that operates based on the power of the electric drive source and switches between the connected state and the disconnected state of the first boom element (141, 142) and the second boom element (142, 143), the drive state includes a first drive state in which the electric drive source rotates in a first direction and a second drive state in which the electric drive source rotates in a second direction, in the first drive state, the first connecting mechanism operates based on an output of the electric drive source, in the second drive state, the second connecting mechanism operates based on an output of the electric drive source, the electric circuit includes a closed circuit including the electric drive source in the braking state, and the braking force is generated by consuming the electric power generated based on rotation of the electric drive source in the closed circuit. a telescopic boom including a first boom element (414, 142) and a second boom element (142, 143) that are telescopically overlapped with each other; an actuator that extends and retracts the telescopic boom; a power source; an electric drive source that is provided in the actuator and drives using power supplied from the power source, a number of the electric drive source is one; an operating unit (45, 46) that operates based on power of the electric drive source; an electric circuit capable of switching between a drive state in which a supply of power from the power source to the electric drive source is allowed to drive the electric drive source, and a braking state in which the supply of power from the power source to the electric drive source stops to generate a braking force to be applied to the electric drive source; and a control unit that controls the switching between the drive state and the braking state, characterized in that the operating unit (45, 46) includes: a first connecting mechanism that operates based on the power of the electric drive source and switches between a connected state and a disconnected state of the first boom element (141, 142) and the actuator; and a second connecting mechanism that operates based on the power of the electric drive source and switches between the connected state and the disconnected state of the first boom element (141, 142) and the second boom element (142, 143), a first connecting mechanism that operates based on the power of the electric drive source and switches between a connected state and a disconnected state of the first boom element (141, 142) and the actuator; and a second connecting mechanism that operates based on the power of the electric drive source and switches between the connected state and the disconnected state of the first boom element (141, 142) and the second boom element (142, 143), the drive state includes a first drive state in which the electric drive source rotates in a first direction and a second drive state in which the electric drive source rotates in a second direction, in the first drive state, the first connecting mechanism operates based on an output of the electric drive source, in the second drive state, the second connecting mechanism operates based on an output of the electric drive source, the electric circuit includes a closed circuit including the electric drive source in the braking state, and the braking force is generated by consuming the electric power generated based on rotation of the electric drive source in the closed circuit.