A comparative study on the generation of 2.45‐GHz multicusp electron cyclotron resonance (ECR) plasma is performed. Looped cusp structures such as the ring‐cusp give a low‐power and low‐pressure ignition, and vice versa, indicating an importance to keep the electron trajetory of gradient‐Bdrift motion inside the chamber even in the case of ECR plasmas. The importance of the antenna location in such multicusp fields is elucidated by comparison in two cases of the axial antenna located in the weak magnetic field region, generating a hydrogen plasma of limited density (ne<7.4×1010cm−3), and a radial antenna located in the strong magnetic field region, generating an overdense plasma (ne∼2×1011cm−3).