An electricity-liquid hybrid liquid-pressure apparatus (1, 1A, 1B, 1C) comprising: a liquid-pressure rotating device configured to cause a rotating shaft to rotate by supply of an operating liquid or configured to eject the operating liquid in accordance with rotation of the rotating shaft, the rotating shaft projecting from a casing of the liquid-pressure rotating device; and an electric rotating device configured to have a power generator function of converting rotational energy of the rotating shaft of the liquid-pressure rotating device into electric energy or an electric motor function of driving the rotating shaft of the liquid-pressure rotating device by supply of the electric energy, wherein: the electric rotating device includes a rotor connected to the rotating shaft, a stator provided around the rotor, and a housing in which the rotor and the stator are accommodated; the rotor and the housing are provided so as to surround the casing; the rotor includes a first accommodating space in which the rotating shaft projecting from the casing is accommodated and the housing includes a second accommodating space in which the stator is accommodated characterized in that the first accommodating space and the inside of the casing of the liquid-pressure rotating device are fluidly connected to each other; a sealing member configured to separate the first accommodating space from the second accommodating space is provided in the rotor; the rotor is rotatably provided at the casing via a first bearing member; and the first bearing member is provided in the first accommodating space. a liquid-pressure rotating device configured to cause a rotating shaft to rotate by supply of an operating liquid or configured to eject the operating liquid in accordance with rotation of the rotating shaft, the rotating shaft projecting from a casing of the liquid-pressure rotating device; and an electric rotating device configured to have a power generator function of converting rotational energy of the rotating shaft of the liquid-pressure rotating device into electric energy or an electric motor function of driving the rotating shaft of the liquid-pressure rotating device by supply of the electric energy, wherein: the electric rotating device includes a rotor connected to the rotating shaft, a stator provided around the rotor, and a housing in which the rotor and the stator are accommodated; the rotor and the housing are provided so as to surround the casing; the rotor includes a first accommodating space in which the rotating shaft projecting from the casing is accommodated and the housing includes a second accommodating space in which the stator is accommodated characterized in that the first accommodating space and the inside of the casing of the liquid-pressure rotating device are fluidly connected to each other; a sealing member configured to separate the first accommodating space from the second accommodating space is provided in the rotor; the rotor is rotatably provided at the casing via a first bearing member; and the first bearing member is provided in the first accommodating space. the electric rotating device includes a rotor connected to the rotating shaft, a stator provided around the rotor, and a housing in which the rotor and the stator are accommodated; the rotor and the housing are provided so as to surround the casing; the rotor includes a first accommodating space in which the rotating shaft projecting from the casing is accommodated and the housing includes a second accommodating space in which the stator is accommodated characterized in that the first accommodating space and the inside of the casing of the liquid-pressure rotating device are fluidly connected to each other; a sealing member configured to separate the first accommodating space from the second accommodating space is provided in the rotor; the rotor is rotatably provided at the casing via a first bearing member; and the first bearing member is provided in the first accommodating space.