The feasibility of steady-state spheromak operation using ECRH current drive is studied numerically. The model used comprises ray tracing and a linear relativistic treatment of current generation. It is assumed that the RF-generated current distribution will relax to that of the spheromak equilibrium. A reactor grade plasma with an average temperature of 18 keV, a density of 0.8 × 1020 m−3, a maximum magnetic field of 4 T and a fusion power of 2100 MW can be sustained by launching less than 100 MW of ECRH power near the plasma surface.