A gas leak detector providing an improved detection of any leaking LPG (Liquid Petroleum Gas) container. There is disclosed a gas leak detector (100) for detecting a leak of gas from a gas container valve unit (111) and/or a leak of gas between a gas container valve unit (111) and a gas cylinder (104) and/or a leak of gas through a wall or a joint in the gas container (104). The gas leak detector has a housing (106), which can be moved relatively to an external surface (107). The housing (105) has a top part (112), a bottom part (114) and a side part (113), the top part (112) and the bottom part (114) can be movable relative to each other. The gas leak detector (100) further has an air flow generator (160) for providing and moving a mixture of air and any leak of gas within a closed loop for improving detection of a gas leak.