The present invention relates to laundry machines, and more particularly, to a control unit assembly in a laundry machine which enables easy assembly and accurate alignment of an input device of a printed circuit board with a button portion of a control panel.The control unit assembly includes a control panel having various operation buttons and coupling portions, a plurality of coating guides coupled to a rear surface of the control panel having fastening portions corresponding to the coupling portions, a plurality of printed circuit boards respectively mounted on the coating guides, each having an electric circuit mounted thereon, joining portions for joining the coating guides together so as to place the coating guides closer to an inside of the control panel, and holders for preventing the coupling portions and fastening portions from moving with respect to each other when the fastening portions are aligned with the coupling portions, thereby improving assembly work, preventing malfunction of the laundry machine, and permitting easy detection of an operation progress.