We present the results of a wide-field survey for extremely red objects (EROs), based on J and R band imaging. The survey covers 2.89 deg2, consisting of 50 single fields, each approximately 210 arcmin2 in size. This survey provides a sample of 60 extended objects with a colour of R-J ≥ 5 and J band magnitudes more than 10σ above background (18^mag≤ J ≤ 20^mag). Thirty five of these objects have been detected in both J and R-band. We derive a surface density for such EROs of 5.7±0.1×10-3 arcmin-2, which is about seven times lower than for galaxies with R-K≥6. Stellar population models suggest that these EROs are massive galaxies with an old stellar population in a redshift range of 1.4≤ z ≤ 3.0. For this scenario, we estimate the co-moving volume density to be (9.57 ± 1.24) ×10-6 Mpc-3.