A cooking device for cooking eggs, comprising: a base having an inlet end and an outlet end, and an accommodating space formed between the inlet end and the outlet end, wherein a transmission direction is defined between the inlet end and the outlet end, a direction from the inlet end to the outlet end is defined as a first transmission direction and a direction from the outlet end to the inlet end is defined as a second transmission direction; a power unit connected to the base; and a multi-stage cooking unit; characterized in that the power unit has a first driving member and a second driving member, the first driving member and the second driving member each having a plurality of rotation shafts, a plurality of sprockets and a plurality of chains, wherein the rotation shafts are rotatably connected to the base and located in the accommodating space, the sprockets are connected to the rotation shafts respectively, and the chains are mounted around the sprockets, a first vertical height existing between one of the rotation shafts that is near the inlet end and a bottom portion of the base, a second vertical height existing between another rotation shaft that is near the outlet end and the bottom portion of the base, wherein the first vertical height is less than the second vertical height; and the multi-stage cooking unit is divided into an upper layer and a lower layer, the multi-stage cooking unit having a plurality of stoppers and at least one guideway, wherein the stoppers are pivotally connected to the second driving members of the power unit, the stoppers of the upper layer are driven by the second driving members to move towards the second transmission direction, the stoppers of the lower layer are driven by the second driving members to move towards the first transmission direction, and the at least one guideway is connected to the base, wherein the stoppers pivotally move to form a carrying spacing or a blanking spacing, and near the outlet end the stoppers pivotally move to output the cooked eggs; wherein heating of the eggs is achieved by boiled water poured into said accommodating space. a base having an inlet end and an outlet end, and an accommodating space formed between the inlet end and the outlet end, wherein a transmission direction is defined between the inlet end and the outlet end, a direction from the inlet end to the outlet end is defined as a first transmission direction and a direction from the outlet end to the inlet end is defined as a second transmission direction; a power unit connected to the base; and a multi-stage cooking unit; characterized in that the power unit has a first driving member and a second driving member, the first driving member and the second driving member each having a plurality of rotation shafts, a plurality of sprockets and a plurality of chains, wherein the rotation shafts are rotatably connected to the base and located in the accommodating space, the sprockets are connected to the rotation shafts respectively, and the chains are mounted around the sprockets, a first vertical height existing between one of the rotation shafts that is near the inlet end and a bottom portion of the base, a second vertical height existing between another rotation shaft that is near the outlet end and the bottom portion of the base, wherein the first vertical height is less than the second vertical height; and the multi-stage cooking unit is divided into an upper layer and a lower layer, the multi-stage cooking unit having a plurality of stoppers and at least one guideway, wherein the stoppers are pivotally connected to the second driving members of the power unit, the stoppers of the upper layer are driven by the second driving members to move towards the second transmission direction, the stoppers of the lower layer are driven by the second driving members to move towards the first transmission direction, and the at least one guideway is connected to the base, wherein the stoppers pivotally move to form a carrying spacing or a blanking spacing, and near the outlet end the stoppers pivotally move to output the cooked eggs; wherein heating of the eggs is achieved by boiled water poured into said accommodating space.