Vapor separator in outboard machine

A vapor separator in an outboard machine in which a fuel within a fuel tank arranged at a position apart from an engine is supplied into a vapor separator by increasing a pressure by means of a low pressure fuel pump, and a pressure of the fuel within the vapor separator controlled to form a fixed liquid surface by a fixed liquid surface control mechanism is increased by a high pressure fuel pump so that the fuel is injected and supplied into an intake pipe connected to the engine via the fuel injection valve, characterized in that a filter (2) is arranged in a bottom portion (1A) of a fuel pump receiving case (1), an upstream chamber (10) of the filter (2) is connected to a portion below the fixed liquid surface of the vapor separator (V) via a fuel inflow passage (1C), a fuel inflow passage (PA) of the high pressure fuel pump (PH) received and arranged within the fuel pump receiving case (1) is connected to and arranged in a downstream chamber (5) of the filter, a vapor discharge chamber (9) separated from the downstream chamber (5) of the filter and facing to a vapor discharge port (PE) of the high pressure fuel pump (PH) is provided in a bottom portion (PF) of the high pressure fuel pump (PH) within the fuel pump receiving case (1), the vapor discharge chamber is communicated with an annular chamber (11) formed between an outer periphery (PG) of the high pressure fuel pump (PH) and an inner periphery (1E) of the fuel pump receiving case (1), and the annular chamber (11) is communicated with a portion below and close to the fixed liquid surface (X-X) of the vapor separator (V) via a vapor discharge passage (1P).