  We have measured magnetic susceptibility and resistivity of
Sr$_{1-x}$Y$_x$CoO$_{3-\delta}$ ($x=$ 0.1, 0.15, 0.2, 0.215, 0.225, 0.25, 0.3,
and 0.4), and have found that Sr$_{1-x}$Y$_x$CoO$_{3-\delta}$ is a room
temperature ferromagnet with a Curie temperature of 335 K in a narrow
compositional range of 0.2 $\leq x\leq$ 0.25. This is the highest transition
temperature among perovskite Co oxides. The saturation magnetization for $x=$
0.225 is 0.25 $\mu_B$/Co at 10 K, which implies that the observed
ferromagnetism is a bulk effect. We attribute this ferromagnetism to a peculiar
Sr/Y ordering.
