I have already tried this solutions :
$the_product = new WC_Product(get_the_ID());
$the_product->get_type(); // Return always "simple"
So, I followed the documentation of the code
* Get the product if ID is passed, otherwise the product is new and empty.
* This class should NOT be instantiated, but the wc_get_product() function
* should be used. It is possible, but the wc_get_product() is preferred.
* @param int|WC_Product|object $product Product to init.
Now I get the correct product type with this:
$the_product = wc_get_product( get_the_ID() );
var_dump( $the_product->get_type() );
The output is correct :