To provide a combustion equipment for a circulation type grain drier capable of shortening the time for clearing up the cause of extinguishment of combustion flame (cause of a failure).

A control unit computes a mean value of a plurality of voltage values detected by a combustion flame monitor unit, and when a mean value detected this time is smaller than that of last time continuously several times, the control unit determines that a flame rod is failed. The control unit also computes a value ΔA obtained by subtracting the mean value of this time from the last mean value, and when an absolute value of ΔA is out of the predetermined threshold value range several times, the control unit determines clogging of a fuel filter. With this structure, since extinguishment of the combustion flame can be thereby detected early before the flame is extinguished, when the combustion flame extinguishes, inspection of the fuel filter and the flame rod is unnecessary, and the time for clearing up causes can be shortened.