Abstract: An in-tank type fuel pump prevents electrical connection from terminals corroding by discharging foreign substances such as water, degraded fuel and the like entering its electrical connector unit. A terminal protrudes outwardly from a pump case inside a cylindrical terminal housing formed integrally with a pump cover of the fuel pump. A hole which is different from a terminal inserting hole is formed at a bottom portion of the terminal housing to permit fluid to flow therethrough and to connect the pump housing with the terminal housing. Therefore, since liquid having a large specific gravity such as water, degraded fuel and the like in the electrical connector unit is discharged to the outside of the electric connecter by the fluid injected to an internal portion of the terminal housing, the terminal of the electric connecter unit can be prevented effectively from corroding.