According to the NHK broadcaster, the sixth outbreak of the bird flu was detected in the prefecture on Saturday morning.
The authorities in Chiba asked the Japan Self-Defence Forces for assistance in culling the chickens. They also introduced a quarantine to prevent the infection from spreading beyond the farm, the broadcaster added.
In January, the national Ministry of Agriculture, Forestry and Fisheries said that the outbreak of bird flu, which started in November, has beat all records in terms of the number of chickens culled in one season. More than seven million birds were exterminated. Seventeen out of Japan's 47 prefectures were affected by the bird flu.