An electroplating apparatus used for a steel pipe having a male thread (Tm) on an outer periphery of an end portion of the steel pipe, the electroplating apparatus comprising: a sealing member configured to be positioned at an end of the steel pipe to seal the steel pipe; a container having an opening to receive the end portion, the container configured to contain the end portion and a plating solution; and an electrode located in the container and configured to face the male thread (Tm); characterized by: a plurality of nozzles positioned within the container and configured to be arranged around a pipe axis of the steel pipe for injecting a plating solution between the male thread (Tm) and the electrode; and a support member located on a side opposite to the opening of the container to support the plurality of nozzles, and in that the support member includes a plating-solution channel for supplying the plating solution to the nozzles, in that each of the nozzles is configured to inject the plating solution in a direction inclined at an angle larger than 20 degrees and smaller than 90 degrees toward the male thread (Tm) relative to a plane perpendicular to the pipe axis, in that the sealing member is fixed to the support member; in that the support member includes a first channel extending along the pipe axis, and in that the sealing member includes: a disc including a second channel extending to an outer periphery thereof and communicating with the first channel; and packing mounted on the outer periphery of the disc and in contact with an inner periphery of the steel pipe. a sealing member configured to be positioned at an end of the steel pipe to seal the steel pipe; a container having an opening to receive the end portion, the container configured to contain the end portion and a plating solution; and an electrode located in the container and configured to face the male thread (Tm); characterized by: a plurality of nozzles positioned within the container and configured to be arranged around a pipe axis of the steel pipe for injecting a plating solution between the male thread (Tm) and the electrode; and a support member located on a side opposite to the opening of the container to support the plurality of nozzles, and a plurality of nozzles positioned within the container and configured to be arranged around a pipe axis of the steel pipe for injecting a plating solution between the male thread (Tm) and the electrode; and a support member located on a side opposite to the opening of the container to support the plurality of nozzles, and in that the support member includes a plating-solution channel for supplying the plating solution to the nozzles, in that each of the nozzles is configured to inject the plating solution in a direction inclined at an angle larger than 20 degrees and smaller than 90 degrees toward the male thread (Tm) relative to a plane perpendicular to the pipe axis, in that the sealing member is fixed to the support member; in that the support member includes a first channel extending along the pipe axis, and in that the sealing member includes: a disc including a second channel extending to an outer periphery thereof and communicating with the first channel; and packing mounted on the outer periphery of the disc and in contact with an inner periphery of the steel pipe. a disc including a second channel extending to an outer periphery thereof and communicating with the first channel; and packing mounted on the outer periphery of the disc and in contact with an inner periphery of the steel pipe.