Provided is an electric waste gate actuator for a turbocharger, in which the inside of a housing is divided into an upper portion and a lower portion to thereby prevent foreign particles generated in a decelerator from being introduced into a driving motor. The electric waste gate actuator for a turbocharger includes: a housing having an installation space inside; a decelerator installed in an upper portion of the installation space; a lever coupled to an upper end of the decelerator and installed outside the installation space; a driving motor installed in a lower portion of the installation space; a blocking plate dividing the installation space into the upper portion, where the decelerator is installed, and the lower portion, where the driving motor is installed, and preventing foreign particles generated in the decelerator from being introduced into the lower portion of the installation space; and a sensor unit installed under the blocking plate to measure a rotation angle of the decelerator.