We performed a mapping observation of the Sunyaev-Zel'dovich effect toward a galaxy cluster, CL0016+16, at 43 GHz using a newly developed 6-beam receiver installed in the Nobeyama 45-m telescope. The temperature decrement of the CMB was measured to be δT
= −0.49 ± 0.06 mK at the center of the cluster. Fitting the isothermal, spherical-symmetrical β -model to the observed temperature decrement distribution, the S-Z effect at the center is inferred to be δT
(0) = −1.0 ± 0.1 mK at the Rayleigh-Jeans limit. This suggests that the Hubble constant is H
0 = 0.5} = 67+16
−11 km s−1 Mpc−1.