A refrigerator comprising: a cabinet defining a storage space; a door for opening and closing the cabinet; a transparent display assembly which covers an opened see-through part of the door, being configured to selectively allow an inner space of the refrigerator to be seen and a screen to be outputted thereon; a display PCB configured for controlling an operation of the transparent display assembly; a voice recognition unit (152, 162) configured to process a user's voice signal; and a microphone for receiving a user's voice input, being connected to the voice recognition unit (152, 162), wherein the display PCB is configured to, according to the user's voice signal, output various screens on the transparent display assembly to correspond to respective processing states of the voice signal, characterized in that: the display PCB is configured to, upon a user's touch manipulation before the user's voice input, display an initial screen on the transparent display assembly, allowing a user's voice input through the microphone, the transparent display assembly being configured to be the brightest or the most transparent state at the initial screen so as to facilitate the viewing of the inside of the refrigerator, the display PCB is further configured to, after the user's voice input, display a voice input standby screen, and the transparent display assembly is configured to be in a more darker or less transparent state at the voice input standby screen than at the initial screen so as to increase readability of the screen outputted on the transparent display assembly. a cabinet defining a storage space; a door for opening and closing the cabinet; a transparent display assembly which covers an opened see-through part of the door, being configured to selectively allow an inner space of the refrigerator to be seen and a screen to be outputted thereon; a display PCB configured for controlling an operation of the transparent display assembly; a voice recognition unit (152, 162) configured to process a user's voice signal; and a microphone for receiving a user's voice input, being connected to the voice recognition unit (152, 162), wherein the display PCB is configured to, according to the user's voice signal, output various screens on the transparent display assembly to correspond to respective processing states of the voice signal, characterized in that: the display PCB is configured to, upon a user's touch manipulation before the user's voice input, display an initial screen on the transparent display assembly, allowing a user's voice input through the microphone, the transparent display assembly being configured to be the brightest or the most transparent state at the initial screen so as to facilitate the viewing of the inside of the refrigerator, the display PCB is further configured to, after the user's voice input, display a voice input standby screen, and the transparent display assembly is configured to be in a more darker or less transparent state at the voice input standby screen than at the initial screen so as to increase readability of the screen outputted on the transparent display assembly. the display PCB is configured to, upon a user's touch manipulation before the user's voice input, display an initial screen on the transparent display assembly, allowing a user's voice input through the microphone, the transparent display assembly being configured to be the brightest or the most transparent state at the initial screen so as to facilitate the viewing of the inside of the refrigerator, the display PCB is further configured to, after the user's voice input, display a voice input standby screen, and the transparent display assembly is configured to be in a more darker or less transparent state at the voice input standby screen than at the initial screen so as to increase readability of the screen outputted on the transparent display assembly.