To provide a brake device, capable of simplifying oil passage constitution, and achieving compactness of a housing.

The braking device is provided with a first oil passage to connect the delivery side of a plunger pump to a boosting valve, a second oil passage to connect the boosting valve to a wheel cylinder, and a third oil passage to connect the delivery side of the plunger pump to an outer side gate valve. The housing has a boosting valve installation hole for installation of the boosting valve, and an outer side gate valve installation hole for installation of the outer side gate valve. A cylinder hole is provided between the boosting valve installation hole and the outer side gate valve installation hole. The boosting valve installation hole and the outer side gate valve installation hole communicate with each other through the cylinder hole.