As Indonesia's population grows, the daily amount of garbage in landfills also increases. Effective garbage classification can maximize the utilization of garbage resources, reduce the amount of garbage disposal, improve the quality of living environment, and reduce the groundwater pollution from garbage. This research aims to design an automatic garbage classification system that use Arduino as a microcontroller and binary tree concept algorithm. The proposed design consists of automatic door, garbage sorter, user interface, and capacity observer. The main components of the system are Microcontroller Arduino Mega 2560, ultrasonic sensor HCSR04, servo motor MG996R, Inductive Proximity Sensor, and Capacitive Proximity Sensor. From the performance test result we can obtain that HC-SR04 ultrasonic sensor as an object detector has an error in distance stabilization of 33.3%, inductive proximity sensors as metal detectors have a 100% success rate, while capacitive proximity sensors as organic garbage detector has a success rate of 85.7%. Overall, the system has a success rate of 86.6% to classify various garbage from 30 experiments using the concept of binary tree in automatic garbage classification.