Disclosed is a vehicle body lower structure which is capable of suppressing an increase in a vehicle weight, ensuring a degree of freedom of a layout of vehicle parts and also protecting an electric power converter. In the vehicle body lower structure, the electric power converter is provided between a first cross member and a second cross member. The electric power converter includes an electric power converter body, a first support portion and a second support portion. The electric power converter is disposed between the first cross member and the second cross member. The first support portion is provided at the electric power converter body and supported by the first cross member. The second support portion is provided at the electric power converter body and supported by the second cross member. The second support portion has a weak portion which is deformable by an impact load.