A fireplace, comprising: a firebox comprising an intake port, an exhaust port, and a window, wherein the window is located between the intake port and the exhaust port; a translucent shield covering the window; a flow guide device provided in the firebox, wherein the flow guide device comprises a separator and two stop plates facing each other; the separator divides the firebox into an air chamber below and a combustion chamber above, wherein the air chamber communicates with the intake port, while a front side of the combustion chamber corresponds to the translucent shield, and communicates with the exhaust port; the separator has a long opening communicating the air chamber and the combustion chamber; each of the stop plates is long, and is located at the opening, wherein a top edge of each of the stop plates is higher than a top surface of the separator; the flow guide device further has at least one first air inlet located below the separator, wherein the at least one first air inlet communicates with the opening; and a combustor adapted to burn gas, wherein the combustor is long, and has a gas outlet provided in a major axial direction thereof; the combustor is located below the separator; the gas outlet corresponds to a space between the stop plates, characterized in that the flow guide device further has a plurality of first air inlets located below the separator, and each of the plurality of first air inlets is formed between two adjacent first separating plates among a plurality of first separating plates which are separately arranged in a reference axial direction, which is parallel to the major axial direction of the combustor and are located on a side of the gas outlet, wherein each of said plurality of first air inlets communicates with the opening. a firebox comprising an intake port, an exhaust port, and a window, wherein the window is located between the intake port and the exhaust port; a translucent shield covering the window; a flow guide device provided in the firebox, wherein the flow guide device comprises a separator and two stop plates facing each other; the separator divides the firebox into an air chamber below and a combustion chamber above, wherein the air chamber communicates with the intake port, while a front side of the combustion chamber corresponds to the translucent shield, and communicates with the exhaust port; the separator has a long opening communicating the air chamber and the combustion chamber; each of the stop plates is long, and is located at the opening, wherein a top edge of each of the stop plates is higher than a top surface of the separator; the flow guide device further has at least one first air inlet located below the separator, wherein the at least one first air inlet communicates with the opening; and a combustor adapted to burn gas, wherein the combustor is long, and has a gas outlet provided in a major axial direction thereof; the combustor is located below the separator; the gas outlet corresponds to a space between the stop plates, characterized in that the flow guide device further has a plurality of first air inlets located below the separator, and each of the plurality of first air inlets is formed between two adjacent first separating plates among a plurality of first separating plates which are separately arranged in a reference axial direction, which is parallel to the major axial direction of the combustor and are located on a side of the gas outlet, wherein each of said plurality of first air inlets communicates with the opening.