A refrigerant cycle device for a vehicle includes a compressor which compresses and discharges refrigerant, a discharge capacity control portion which controls a discharge capacity of the compressor. The refrigerant cycle device further includes a noise determination portion which determines whether an audible noise other than a refrigerant passing noise is in a low noise state, and/or a load determination portion which determines whether an air-conditioning thermal load is in a high load state. The discharge capacity control portion performs a gradual activation control in which the discharge capacity of the compressor is set to be lower than that determined in a normal control, when the noise determination portion determines that the audible noise is in the low noise state, and/or when the load determination portion determines that the air-conditioning thermal load is in the high load state, at an activation time of the compressor.