A loop heat pipe (LHP) is used as the heat transport device to reject heat from the Monitor of All-sky X-ray Image (MAXI) . Since this LHP was designed exclusively for the MAXI system, it is different from conventional LHPs [2-4] in the configuration that it has two-condensers connected in parallel to a common evaporator. Each of the radiators has different radiation area and thus the different pipe length of the condenser. It is anticipated that the thermal condition of each condenser may be independent of each other because they point toward different directions. We experimentally investigated the effects of the particular design of this LHP on the heat transfer performance on the ground. Especially, we focus on the start-up behavior from a low power state that might be one of the technical concerns for the LHP.