The present invention relates to a method for inducing a merge candidate block and a device using same. An image decoding method involves decoding motion estimation region (MER) related information; determining whether or not a predicted target block and a spatial merge candidate block are included in the same MER; and determining the spatial merge candidate block to be an unavailable merge candidate block when the predicted target block and the spatial merge candidate block are included in the same MER. Accordingly, by parallely performing the method for inducing a merge candidate, parallel processing is enabled and the computation amount and implementation complexity are reduced.