It's difficult to pinpoint the very first illustrated book for children with absolute certainty, as early forms of picture books existed long before printing was invented. However,
the earliest printed book specifically designed for children, with illustrations, is widely considered to be "Orbis Sensualium Pictus" by the Czech educator Comenius, published in 1658.
This book contained images and text explaining various objects, animals, and concepts, and it was a groundbreaking work in terms of using visual aids for learning.
While there were earlier books with illustrations, "Orbis Sensualium Pictus" is recognized for its specific focus on educating children and its widespread impact on early childhood education.