A deflection device for a projection tube includes a main deflection device for generating a raster and an auxiliary deflection device for correcting a convergence. The auxiliary deflection device includes a toroidal auxiliary horizontal coil, a saddle-type auxiliary vertical coil, and a ferrite core. According to this configuration, the deflection efficiency is enhanced, and pincushion distortion in upper and lower portions can be corrected efficiently while a change in the shape of a beam spot is reduced.