A solar cell is discussed, which includes a tunneling layer on one surface of a semiconductor substrate; a first conductive type region on the tunneling layer; a second conductive type region on the tunneling layer; a first electrode and a second electrode, the first electrode connected to the first conductive type region and the second electrode connected to the second conductive type region. The tunneling layer includes a first portion and a second portion. The first portion is disposed to correspond to at least a part of the first and second conductive type regions and has a first thickness. At least a part of the second portion is disposed to correspond to a boundary portion between the first conductive type region and the second conductive type region. The second portion has a second thickness greater than the first thickness.