A bucket elevator type continuous ship unloader is used for both a sidewise shovelling operation and a catenary cleaning up operation. In this ship unloader, a bucket chain is wound around sprockets respectively provided at the front and rear ends of a horizontal frame and a sprocket provided above the rear sprocket such that it encircles the sprockets in an L-shaped form. The bucket chain is made loosened or taut by the upward or downward movement of the horizontal frame with respect to the upper sprocket. The horizontal frame is provided with a horizontal rail with which a roller provided on each bucket is fitted when the bucket chain is stretched tautly. During the sidewise shovelling operation, the buckets run while being guided by the rail. In consequence, the force acting on the bucket during the shovelling in the vertical direction as well as in a direction transverse to the direction of movement of the bucket is exerted on the rail. So, a bucket chain which is only strong enough to pull the buckets is required. This means that a bucket chain which is so rigid as required in the prior art is not necessary, and the weight of the bucket chain can be reduced.