Memory leaks!

I have such a code and I wonder how should I clean up after it? Should I delete all elements one by one? Should I delete also layouts? Or can I delete just the main element - parent of every other and hope that he will clean up the rest of them?

Code:

TableTab::TableTab(QWidget *parent) :
    QWidget(parent)
{
    objectNameLabel_ = new QLabel;
    personLabel_ = new QLabel;
    tableWidget_ = new RequestTable(parent);
    summaryBox_ = new QGroupBox;
    commentaryTextEdit_ = new QPlainTextEdit;
    normatywLabel_ = new QLabel;
    sumLabel_ = new QLabel;
    reInvoiceLabel_ = new QLabel;
    QGroupBox *calculationsBox = new QGroupBox;
 
    objectNameLabel_->setText("OBIEKT 1");
    personLabel_->setText("JOLA");
    normatywLabel_->setText("666");
    sumLabel_->setText("667");
    reInvoiceLabel_->setText("668");
 
    QBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(normatywLabel_);
    layout->addWidget(sumLabel_);
    layout->addWidget(reInvoiceLabel_);
    calculationsBox->setLayout(layout);
 
    layout = new QHBoxLayout;
    layout->addWidget(commentaryTextEdit_);
    layout->addWidget(calculationsBox);
    summaryBox_->setLayout(layout);
 
    layout = new QVBoxLayout;
    layout->addWidget(objectNameLabel_);
    layout->addWidget(personLabel_);
    layout->addWidget(tableWidget_);
    layout->addWidget(summaryBox_);
    setLayout(layout);
}