This book covers the syllabus of undergraduate degree course titled "Industrial Electronics". This book will serve as a reference to the engineering students, diploma for the basic concepts of electronics. This book is written in a simple language and it is very easy to understand the concepts. This book is published in black and white. This book contains five units. Unit-1 covers the basic concepts of semiconductors and PN diodes. Unit-2 covers Bi-polar junction transistor. Unit-3 covers about rectifiers, filters and voltage regulators. Unit-4 covers welding and heating. Unit-5 covers the concepts of ultrasonics.Important questions have been given at the end of each unit, which is very much helpful for the students in their external examinations.We are grateful to Lambert Publications for getting the manuscript reviewed by experts and providing a feedback to publish the book.