The present invention relates to an inter-layer prediction method, and an encoder and a decoder using the same, the inter-layer prediction method including specifying a reference block in a reference layer and predicting a current block in a current layer using information on the reference block, wherein the specifying of the reference block includes specifying the reference block on the basis of a reference position which is a position in the reference layer corresponding to a current position in the current layer for specifying the current block.