A reformer for reforming dry distillation gas, the reformer comprising: a reformer vessel comprising a mounting surface; a dry gas inlet for introducing dry distillation gas into the reformer vessel, a reformed gas outlet for discharging reformed gas defined as the dry distillation gas after being reformed, an oxidizer inlet for introducing oxidizer into the reformer vessel, each of which are provided on the reformer vessel; a punching plate for holding heat storage material which is installed on parts of the plurality of the heat receiving pipes, the parts being in the reformer vessel; and heat storage material placed on the punching plate for holding heat storage material, characterized in that the reformer further comprises: a plurality of heat receiving pipes attached to the reformer vessel so that their upper parts make a plane level to the mounting surface of the reformer and they pass through the reformer vessel; a plurality of hot air exhaust pipes each having portion that is kept in a space of the reformer vessel over the punching plate for holding heat storage material, the portion having a plurality of through holes in its pipe wall; and a connecting part connecting the plurality of the hot air exhaust pipes and the plurality of the heat receiving pipes so to allow air which passes through the plurality of the heat receiving pipes to be discharged from each through hole of each hot air exhaust pipe. a reformer vessel comprising a mounting surface; a dry gas inlet for introducing dry distillation gas into the reformer vessel, a reformed gas outlet for discharging reformed gas defined as the dry distillation gas after being reformed, an oxidizer inlet for introducing oxidizer into the reformer vessel, each of which are provided on the reformer vessel; a punching plate for holding heat storage material which is installed on parts of the plurality of the heat receiving pipes, the parts being in the reformer vessel; and heat storage material placed on the punching plate for holding heat storage material, characterized in that the reformer further comprises: a plurality of heat receiving pipes attached to the reformer vessel so that their upper parts make a plane level to the mounting surface of the reformer and they pass through the reformer vessel; a plurality of hot air exhaust pipes each having portion that is kept in a space of the reformer vessel over the punching plate for holding heat storage material, the portion having a plurality of through holes in its pipe wall; and a connecting part connecting the plurality of the hot air exhaust pipes and the plurality of the heat receiving pipes so to allow air which passes through the plurality of the heat receiving pipes to be discharged from each through hole of each hot air exhaust pipe. a plurality of heat receiving pipes attached to the reformer vessel so that their upper parts make a plane level to the mounting surface of the reformer and they pass through the reformer vessel; a plurality of hot air exhaust pipes each having portion that is kept in a space of the reformer vessel over the punching plate for holding heat storage material, the portion having a plurality of through holes in its pipe wall; and a connecting part connecting the plurality of the hot air exhaust pipes and the plurality of the heat receiving pipes so to allow air which passes through the plurality of the heat receiving pipes to be discharged from each through hole of each hot air exhaust pipe.